Yep, everything is bigger here.
- In a mixing bowl combine buttermilk, eggs, vanilla, and baking soda. Whisk until smooth and set aside.
- In another mixing bowl combine then sift flour, sugar, cinnamon, and salt. Set aside.
- Bring to boil in saucepan unsalted butter, vegetable shortening, cocoa, and water.
- Pour hot mixture over flour mixture and stir vigorously with a wooden spoon. Add buttermilk mixture and stir to thoroughly incorporate.
- Pour batter in buttered and floured half-sheet-cake pan (about 15 x 10) and bake at 400 degrees for 20 minutes or until edges of cake pull away from the pan and the cake springs back when you touch it.
- About 10 minutes before the cake is done, bring to a boil unsalted butter, buttermilk, and cocoa.
- Quickly remove from heat (it will not be pretty) and add vanilla and powdered sugar; beat with an electric mixer till smooth.
- Stir in pecan pieces.
- Spread icing over hot cake (this is important). Allow to cool, then cut into squares and serve.